A mysterious object, 1991 VG, which has left scientists scratching their heads since it was first discovered by astronomer James Scotti in November 6, 1991, will pass Earth in the summer of 2017. Based on its unusual features and properties, some scientists considered 1991 VG a candidate object in the ongoing search for an alien spacecraft or probe in our solar system at the time it was first discovered.

Scotti discovered the mysterious, small, fast moving space object with unusual features in November 1991 while searching the skies for asteroids at the University of Arizona’s Kitt Peak National observatory.

The object, only about 10 meters in diameter, exhibited strange properties that raised the astronomer’s suspicion. It moved faster than expected for a space object its size and had an unusually fast rate of rotation. It also exhibited an anomalous pattern of brightness variation that suggested it was not an ordinary main-belt asteroid, according to Motherboard.

Scotti tracked the mysterious object for two nights, collecting data needed to plot its orbit. He was surprised to find that it had a heliocentric orbit strikingly similar similar to Earth’s. He was also surprised to find that it was due to brush past Earth at a distance of 280,000 miles the following month and that it had already passed close to Earth at least once in the past. Data plotting 1991 VG’s orbital trajectory showed that it passed Earth around March 1975.

The information was surprising because 1991 VG was the only known “asteroid-like” body with a heliocenteric orbit similar to Earth’s, according to NASA. And although small asteroids passing close to Earth are not uncommon, they tend to be very short-lived because they are prone to impacting the planet or be thrown out into a different orbital path by Earth’s gravitation field.

In short, 1991 VG’s combination of properties and features suggested to Scotti and his colleagues that it could be an artificial object built by someone and launched to space. But although the scientists admitted frankly that 1991 VG could be an alien spacecraft or probe operating in our solar system, they were unwilling to concede the suggestion without overwhelming evidence supporting it. The scientists thus looked instead at the possibility that it was a part or section of a man-made craft — such as an Apollo 12 rocket — launched into space decades ago.

Scotti, however, acknowledged that researchers were pushed further towards admitting unreservedly that 1991 VG could be an alien spacecraft after eliminating practically all possible man-made spacecraft and rocket bodies that might be 1991 VG.

“There were a few possible spacecraft and rocket bodies that might be 1991 VG, but when we looked into each, we were able to eliminate each of them.”

Still unwilling to concede the likelihood that 1991 VG could be an alien spacecraft, researchers began investigating the possibility that it could be a small asteroid with unusual features that simulate an artificial space probe.

Despite scientists’ reservations about declaring the object an alien probe ahead of irrefutable evidence that could emerge during observation as it passes close to Earth in the summer 2017, there was excitement among members of the online UFO community who hoped that we could obtain irrefutable evidence of UFOs and extraterrestrial life when 1991 VG passes close to Earth later in 2017.

But skeptics suggested in a Reddit forum that 1991 VG could be a rocket that the Soviets launched secretly into space during the Cold War.

“The Soviets had rockets as powerful as American rockets, were quite fond of covering things up when they went badly, and were attempting to get to the moon themselves,” a skeptic argued on Reddit.

“It is plausible that a forgotten Russian mission resulted in this object.”

However, conspiracy theory speculation that 1991 VG could be an alien spacecraft positioned in heliocentric orbit to collect data about conditions on Earth during regular flybys got a big boost when, in 1995, Duncan Steel, an astronomer at the University of Adelaide, argued in an article published in The Observatory that evidence appeared to support the alien probe theory.

According to Steele, the fact that no known “man-made rocket bodies left in heliocentric orbits during the space age have purely gravitational orbits returning to the Earth [in November of 1991]” meant that the mysterious object could be regarded as a prime candidate as an alien space probe exploring our solar system.

“It might be argued that 1991 VG is a candidate as an alien probe observed in the vicinity of our planet.”

But Steele attempted to douse the flaring flames of conspiracy theory speculation by arguing that he raised the theory that 1991 VG could be an alien artifact only as way of finding a more likely alternative explanation. He argued subsequently that 1991 VG was more likely a man-made object, such as a section of an Apollo 12 rocket.

“I do not think [VG 1991] is of extraterrestrial origin,” Steel said, according to Motherboard. “I do think that we should take seriously the possibility that there are alien artifacts in the solar system, although I very much doubt that there are any, based on what we know so far.”

But conspiracy theorists dismissed Steel’s arguments, saying that he was merely engaging in double-talk out of fear that subscribing unreservedly to the alien object explanation of 1991 VG could expose him to censure by his professional colleagues. According to conspiracy theorists and Search for Extraterrestrial Artifacts (SETA) enthusiasts, it is likely that close observation of 1991 VG during the next flyby in the summer of 2017 will prove that it is an alien spacecraft or probe exploring our solar system.

But other astronomers, such as Scotti, insisted that close observation during the flyby in 2017 will likely show that 1991 VG is a natural space object, such as a small asteroid. But some researchers pointed out that the natural object theory was contradicted by the pattern of brightness fluctuation of 1991 VG at the time it was observed. The pattern of variation in brightness suggested that 1991 VG was rotating very rapidly. According to experts, a natural body rotating as fast as 1991 VG would likely fly apart due to excessive centrifugal forces.

But subsequent research showed that small asteroids under 100 feet with monolithic structures are able to rotate very fast without disintegrating. This increased the chances that 1991 VG is a small monolithic space rock.

“Where did 1991 VG come from and how did it get into its present orbit?” Scotti mused while exploring the possibility that 1991 VG is small asteroid with a monolithic structure. “One possibility would be that it is ejecta from a lunar impact. Another possibility is that the Yarkovsky force, caused by the thermal emissions of a rotating object, systematically pushed the object around over long times. It’s still a puzzle!”

But scientists hope that the puzzle will be resolved in the summer of 2017 when 1991 VG makes another Earth flyby. Meanwhile, alien hunters are holding their breath in anticipation of a major breakthrough in the decades-old search for extraterrestrial artifacts (SETA).

Space object 1991 VG will be observable from the southern hemisphere during its next flyby in the summer of 2017.